The present invention relates to a method for the artificial cultivation of white mushrooms and to a strain of white fruiting body.
Lyophyllum ulmarium is an edible mushroom of excellent flavor belonging to Tricholomataceae, Tribus Lyophylleae, Lyophyllum ["Genshoku Nihon Shinkinrui Zukan (I)" written by Imazeki and Hongo and published from Hoikusha (1987)].
As kinds of edible mushroom commonly used at present, there may be mentioned, Lentinus edodes, Flammulina venutipes, Pleurotus ostreatus, Agricus biosporus and Lyophyllum ulmarium, all of which are supplied in large quantities by artificial cultivation. Of these, most Flammulina velutipes placed in the market is white in color, and champignons are also white in color. Thus, white-colored mushrooms occupy a large part of commercially available edible mushrooms and are highly evaluated in the food market.
In nature, Lyophyllum ulmarium grows caespitose or singly on the dead or live wood of a variety of broad-leaved trees in autumn, and this mushroom has long been harvested for food because of its nice shape, crispy texture and excellent flavor. In recent years, artificial cultivation in a bottle or box using a sawdust-medium comprising rice bran has been established, which ensures steady harvest of Lyophyllum ulmarium throughout the year without regard to the season. In this sawdust-medium cultivation, primordia are formed after a "Kinkaki" operation ( an operation which promotes the formation of fruiting ) , and cultivation is continued until harvest of the fruit bodies can be done.
The present inventors formerly established this method for artificial cultivation of Lyophyllum ulmarium and provided a strain of Lyophyllum ulmarium suitable for the artificial cultivation [Japanese Patent Kokai No.273467/1988 (U.S. Pat. No.4940837)]. However, the cap color is all brown (though different in color shade) in the strains of Lyophyllum ulmarium distributed in nature and in the strain used for artificial cultivation, and no strain of Lyophyllum ulmarium having white caps is known. Thus, there has been a demand for the supply of mushroom with white fruiting body in the food market because of diversified cooking.
Under the above-described circumstances, the present invention is intended to provide a simple method for industrially producing white fruiting bodies of Lyophyllum ulmarium (mushroom of high edibility value), and to provide a strain of white fruiting body.